JP5820358B2 - Indirect heating drying method of granular material, modified coal manufacturing method, indirect heating type drying apparatus, and modified coal manufacturing apparatus - Google Patents

Description

  The present invention relates to an indirect heating drying method for granular materials, a method for producing modified coal, an indirect heating type drying apparatus, and a modified coal manufacturing apparatus.

  Porous coal with a high water content has a low calorific value. Therefore, a production method for obtaining modified coal from such porous coal has been developed (see JP-A-7-233383). This manufacturing method will be described. First, porous charcoal (raw coal) is pulverized and granulated, and then mixed with a mixed oil containing heavy oil and solvent oil to obtain a raw slurry. Next, the raw slurry is preheated and then heated to advance the dehydration of the porous coal, and the mixed oil is impregnated into the pores of the porous coal to obtain a dehydrated slurry. Thereafter, the modified porous charcoal and the mixed oil are separated from the dewatered slurry, and then the modified porous charcoal is dried (drained). The dried modified porous coal is cooled and shaped as desired. On the other hand, the mixed oil recovered at the time of separation from the dehydrated slurry and drying is reused as the circulating oil and used again as the raw material slurry.

  In the method for producing modified coal, drying of the granular modified porous coal separated from the dewatered slurry is usually performed using an indirect heating dryer. As this indirect heating type dryer, a so-called steam tube dryer is frequently used from the viewpoints of drying ability and operability. The steam tube dryer includes a rotating cylinder provided rotatably around an axis, a plurality of heating pipes disposed in parallel to the axis within the rotating cylinder, and carrier gas from one side of the rotating cylinder. Carrier gas distribution means for supplying and discharging to the other side. As a drying method of the granular material using such an indirect heating type dryer, two indirect heating type dryers are used, and in the first indirect heating type dryer, the flow is parallel to the flow of the granular material. The carrier is supplied with a carrier gas to dry the particulate matter, and then, in a second indirect heating type dryer, the carrier gas is supplied so as to be countercurrent to the flow of the particulate matter, Further drying methods have been proposed (see Japanese Patent Application Laid-Open No. 2009-97783). Thus, by using two indirect heating type dryers, it is supposed that the adhesion of a granular material to a heating tube can be suppressed and the dried material of the stable liquid content can be obtained. Further, in this drying method, the first bag filter is used for collecting the carrier gas discharged from the first indirectly heated dryer, and the first bag filter is used for collecting the carrier gas discharged from the second indirectly heated dryer. Using a two-bag filter, each collected dust (fine particles) is mixed with a dried product (granular material) discharged from the first indirectly heated dryer and dried with a second indirectly heated dryer.

  The yield of the product (dried product) is increased by drying the dust collected in this manner again to obtain a dried product. However, in particular, in the second indirect heating type dryer that dries the granular material that has been dried to some extent, the fine particles accompanying the carrier gas increase. Therefore, the accumulation of dust (fine particles) in the second bag filter increases the pressure loss in the bag filter, disturbing the pressure balance of the carrier gas and hindering stable operation of the process, This will lead to a decrease in the service life. Further, the pressure balance of the carrier gas is disturbed and a part of the system becomes a negative pressure, so that air is mixed in, and the dry matter may be ignited due to an increase in oxygen concentration.

  On the other hand, the modified coal obtained by the above production method is likely to generate dust due to the presence of dry fine particles. Therefore, although water is sprayed on the obtained modified coal, a large amount of water is required, and there is a disadvantage that the amount of heat generation is reduced by water spraying.

JP 7-233383 A JP 2009-97783 A

  The present invention has been made based on the above-described circumstances, and an indirect heating drying method that can enhance the stability of the pressure balance of the carrier gas when the granular material is dried using an indirect heating dryer, and It aims at providing the manufacturing method of modified coal. Another object of the present invention is to provide an indirect heating type drying apparatus and a modified coal manufacturing apparatus capable of performing such a drying method and a manufacturing method.

The invention made to solve the above problems is
A rotating cylinder provided rotatably around an axis, a plurality of heating pipes arranged in parallel to the axis in the rotating cylinder, and a carrier gas supplied from one side of the rotating cylinder and discharged to the other side Two indirect heating dryers each having a carrier gas distribution means
(A) In the first indirect heating type dryer, a carrier gas is supplied so as to be parallel to the flow of the granular material, and the granular material is dried, and (B) a second indirect heating type dryer. In the method for indirectly heating and drying a granular material, the method includes a step of supplying a carrier gas so as to be countercurrent to the flow of the granular material, and further drying the granular material to obtain a dried granular material,
(C) collecting the first fine particles contained in the carrier gas discharged from the first indirect heating type dryer and mixing with the particulate matter provided to the step (B), and (D) the second The method further includes the step of collecting the second fine particles contained in the carrier gas discharged from the indirect heating dryer and mixing with the dried granular material obtained in the step (B).

  In the method of indirectly heating and drying the granular material, in the step (D), the second fine particles contained in the carrier gas discharged from the second indirectly heated dryer are again supplied to the second indirectly heated dryer and dried. It mixes with the dry granular material obtained at the said (B) process, without making it. By doing in this way, the amount of the second fine particles contained in the carrier gas discharged from the second indirect heating dryer can be reduced, and the second to the bag filter or the like used for recovery of the second fine particles. Accumulated amount of fine particles can be reduced. Therefore, according to the indirect heat drying method, the stability of the pressure balance of the carrier gas can be enhanced. Further, since the second fine particles have a small particle size among the granular materials to be dried and the drying is sufficiently advanced, the indirect heating drying method has a higher drying efficiency than the conventional drying method. It does not substantially lower.

  Furthermore, according to the indirect heat drying method, only the second fine particles once separated can be treated, and the treated second fine particles can be mixed with the dried granular material obtained in the step (B). Examples of such treatment include spraying water on the second fine particles and mixing with an adhesive. By such treatment, it is possible to effectively suppress the dust generation of the dried granular material and to improve the moldability when forming into a briquette or the like.

  The average particle diameter of the second fine particles recovered in the step (D) is preferably 10 μm or less. Since the fine particles having such a particle diameter are relatively sufficiently dried in the step (A), a decrease in drying efficiency can be suppressed in the indirect heat drying method. In addition, since particularly fine particles in the above range are likely to be clogged in the bag filter, the stability of the pressure balance of the carrier gas can be further improved by collecting such particles.

  The mass ratio between the second fine particles recovered in the step (D) and the dried granular material obtained in the step (B) is preferably 1:99 or more and 1: 3 or less. By separating such an amount of the second fine particles, it is possible to improve both the stability of the pressure balance of the carrier gas and to suppress the reduction of the drying efficiency.

The method for producing the modified coal of the present invention comprises:
(Α) a step of mixing raw material porous carbon and oil to obtain a raw slurry;
(Β) heating the raw material slurry to obtain a dehydrated slurry;
(Γ) a process for separating the dehydrated slurry into modified porous coal and oil, and (δ) a step of drying the separated modified porous coal,
In the step (δ), an indirect heating drying method for the granular material is used.

  According to the modified coal production method, the modified porous coal is dried using the indirect heating drying method of the particulate matter, so that the stability of the pressure balance of the carrier gas can be improved, and thus the productivity can be improved. it can.

Indirect heating type drying apparatus of the present invention,
Equipped with a first indirect heating dryer and a second indirect heating dryer,
Each of the indirect heating dryers includes a rotating cylinder that is rotatably provided around an axis, a plurality of heating tubes that are disposed in the rotating cylinder in parallel with the axis, and a carrier gas that is supplied to the rotating cylinder. Carrier gas distribution means for supplying from one side and discharging to the other side,
Arranged to receive the dried product obtained from the first indirectly heated dryer as the material to be dried of the second indirectly heated dryer,
The carrier gas distribution means is configured so that the flow of the material to be dried in each indirect heating dryer is a parallel flow in the first indirect heating dryer and a countercurrent in the second indirect heating dryer. An indirect heating type drying apparatus for supplying gas,
A first recovery means for recovering the first fine particles contained in the carrier gas discharged from the first indirectly heated dryer;
A first mixing means for mixing the first fine particles with the granular material provided to the second indirect heating type dryer;
Recovery means for recovering the second fine particles contained in the carrier gas discharged from the second indirectly heated dryer, and second mixing means for mixing the second fine particles with the dried product obtained from the second indirectly heated dryer Is further provided.

  By using the indirect heating type drying apparatus, the indirect heating drying method of the granular material can be efficiently performed.

The modified coal production apparatus of the present invention is
Mixing means for mixing granular porous charcoal and oil to obtain a raw material slurry,
Heating means for heating the raw material slurry to obtain a dehydrated slurry;
A reformed coal production apparatus comprising solid-liquid separation means for separating the dewatered slurry into modified porous coal and oil, and drying means for drying the separated modified porous coal,
The drying means is the indirect heating type drying apparatus.

  By using the modified coal production apparatus, the method for producing the modified coal can be efficiently performed.

  Here, “drying” means reducing the content of the liquid contained in the material to be dried, and this liquid is not limited to water. The “average particle diameter” refers to a cumulative 50% average volume diameter (median diameter).

  As described above, according to the method for indirectly heating and drying a granular material of the present invention, the stability of the pressure balance of the carrier gas can be increased, and according to the method for producing a modified coal of the present invention using the method. As a result, the productivity of the modified coal can be increased. Moreover, the indirect heating type drying apparatus and the modified coal manufacturing apparatus of the present invention can efficiently perform such an indirect heating drying method and a modified coal manufacturing method.

Schematic which shows the indirect heating type drying apparatus which concerns on one Embodiment of this invention. The typical perspective view which shows the steam tube dryer with which the indirect heating type drying apparatus of FIG. 1 is provided. The flowchart which shows the manufacturing method of the modified coal which concerns on one Embodiment of this invention.

  Hereinafter, the indirect heating type drying apparatus, the indirect heating type drying method, the modified coal production apparatus, and the modified coal production method of the present invention will be described in detail with reference to the drawings as appropriate.

<Indirect heating dryer>
The indirect heating type drying apparatus 1 of FIG. 1 mainly includes a first indirect heating type dryer 2, a second indirect heating type dryer 3, a first bag filter 4, and a second bag filter 5.

  Specific examples of the first and second indirectly heated dryers 2 and 3 include a steam tube dryer 100 shown in FIG. The steam tube dryer 100 mainly includes a rotating cylinder 101, a plurality of heating tubes 102, a supply port 103 and a discharge port 104 for an object to be dried, and a carrier gas supply port 105 and a carrier gas discharge port 106 as carrier gas circulation means. .

  The dimension of the steam tube dryer 100 is not particularly limited. In general, the length of the rotating cylinder 101 is 5 m or more and 30 m or less. In this rotating cylinder 101, the granular material which is to be dried is brought into contact with the heating tube 102 heated from the inside by the heat medium. The steam tube dryer 100 is configured to sequentially move the objects to be dried toward the discharge port 104 as the rotary cylinder 101 rotates. Accordingly, the rotating cylinder 101 is installed with a slight downward slope in order to smoothly transfer the material to be dried from the material supply port 103 at one end to the discharge port 104. The rotating cylinder 101 is supported on the supporting rollers 108a and 108b respectively provided on the two bases 107a and 107b via the rings 109a and 109b. The downward slope is adjusted by the height and angle of the two bases 107a and 107b and the supporting rollers 108a and 108b. In order to rotate the rotating cylinder 101, a driven gear 110 is provided around the rotating cylinder 101. The drive gear 111 is engaged with the driven gear 110, the rotational force of the prime mover 112 is transmitted through the speed reducer 113, and the rotary cylinder 101 rotates about its axis.

  A large number of heating tubes 102 are arranged in the rotary cylinder 101 in parallel with the axis. Heated steam as a heat medium is supplied to these heat pipes 102 through a heat medium inlet pipe 115 attached to the rotary joint 114. The heated steam is circulated through each heating pipe 102 and then discharged through the heat medium outlet pipe 116.

  On the other hand, the evaporated liquid component from the material to be dried rides on the carrier gas G and is discharged out of the rotating cylinder 101. Specifically, in the tube dryer 100, the carrier gas G is supplied from the supply port 105 on the dry matter discharge side and is discharged from the discharge port 106 on the dry matter supply side. In this case, the flow of the carrier gas G is countercurrent to the flow of the material to be dried.

  In the tube dryer 100, the carrier gas supply port and the discharge port can be reversed, that is, the carrier gas can be supplied in the opposite direction. By doing in this way, the flow of carrier gas can be made into the parallel flow with respect to the flow of a to-be-dried object.

The carrier gas G is not particularly limited, and can be appropriately selected according to the type of the object to be dried. In the case the material to be dried is flammable, it is possible to use a inert gas such as N _2.

  The first indirect heating type dryer 2 and the second indirect heating type dryer 3 accept the dried product obtained from the first indirect heating type dryer 2 as the material to be dried of the second indirect heating type dryer 3. That is, they are arranged in series. In the first indirectly heated dryer 2, the carrier gas G and the material to be dried (granular material A) flow in the same direction (cocurrent flow). In the second indirectly heated dryer 3, the carrier gas The carrier gas is supplied so that the flow of G and the material to be dried (granular material A) is in the opposite direction (counterflow).

The first bug filter 4 and the second bug filter 5 are not particularly limited, and known ones can be used. The first bag filter 4, a first recovery unit to recover the first fine particles D ₁ included in the carrier gas G discharged from the first indirect heating type dryer 2. Second bag filter 5, as a second recovery unit to recover the second fine particles D ₂ contained in the carrier gas G discharged from the second indirect heating type dryer 3.

Furthermore, the indirect heating type drying apparatus 1 includes a first mixing unit and a second mixing unit (not shown). Said first mixing means mixes the granules A to be subjected to the first fine particles D ₁ to the second indirect heat type dryer 3. Also, the second mixing means for mixing the second particles D ₂ of the dry product obtained from the second indirect heating type dryer 3 (dry granulate B). Each mixing means is not particularly limited as long as it can mix them, and facilities and equipment that can transport fine particles such as a suction loader, a hopper loader, and various conveyors can be used. Moreover, the piping etc. which utilized the height difference may be sufficient. The mixing does not have to be a mixture of two types (fine particles and particulates) in a uniform state, and it is only necessary that the two types exist together.

  In addition, the other apparatus with which the indirect heating type drying apparatus 1 is provided is demonstrated along description of the following indirect heating type drying methods.

<Indirect heating type drying method>
Indirect heating type drying method of the present invention,
Using two indirect heating dryers,
(A) In the first indirect heating type dryer, a carrier gas is supplied so as to be parallel to the flow of the granular material, and the granular material is dried,
(B) In the second indirect heating type dryer, a carrier gas is supplied so as to be countercurrent to the flow of the granular material, and the granular material is further dried to obtain a dry granular material,
(C) collecting the first fine particles contained in the carrier gas discharged from the first indirect heating type dryer and mixing with the particulate matter provided to the step (B), and (D) the second Recovering the second fine particles contained in the carrier gas discharged from the indirect heating dryer and mixing with the dried granular material obtained in the step (B).

  Hereinafter, the details of the indirect heating type drying method will be described in detail as an example using the indirect heating type drying apparatus 1 of FIG.

(A) Process The granular material A which is a to-be-dried material is supplied to the 1st indirect heating type dryer 2 through the screw conveyor 6. FIG. In the first indirect heating type dryer 2, the carrier gas G is supplied so as to be parallel to the flow of the granular material A. The granular material A dried by the first indirect heating type dryer 2 is conveyed from the discharge casing 7 to the conveyor 8 and supplied to the second indirect heating type dryer 3 by the conveyor 8.

In the step (A), the carrier gas G is supplied to the first indirect heating dryer 2 from the supply side of the granular material A. This carrier gas captures the evaporated liquid from the granular material A and the dust (first fine particles D ₁ ) entrained as the granular material A is dried in the dryer 2. And this carrier gas G is discharged | emitted from the discharge | emission side of the dried material (granular material A) of the 1st indirect heating type dryer 2. FIG.

(B) Process Next, the said granular material A is further dried with the 2nd indirect heating type dryer 3, and the dry granular material B is obtained. In the 2nd indirect heating type dryer 3, carrier gas G is supplied so that it may become countercurrent with respect to the flow of a granular material. The dried granular material B is discharged from the discharge casing 9 and stored as necessary.

In the step (B), the carrier gas G is supplied to the second indirectly heated dryer 3 from the discharge side of the dried product (dried granular product B). This carrier gas captures the evaporated liquid component from the granular material and the dust (second fine particles D ₂ ) entrained as the granular material is dried in the dryer 3. And this carrier gas G is discharged | emitted from the supply side of the granular material A of the 2nd indirect heating type dryer 3. FIG.

(C) Process The carrier gas G discharged from the first indirectly heated dryer 2 is sent to the first bag filter 4. In the first bag filter 4, the first fine particles D ₁ contained in the carrier gas G are collected.

The indirect heating type drying apparatus 1 is provided with an N ₂ blaster 10 in the vicinity of the inlet of the first bag filter 4. The N ₂ blaster 10 removes dust (first fine particles D ₁ ) adhering to or depositing on the inlet of the first bag filter 4 and the pipe connecting the first indirect heating dryer 2 and the first bag filter 4. Can do.

The recovered first particles D ₁ was, due first mixing means (not shown), is mixed with granules A to be subjected to the step (B). At this time, the first fine particles D _1, for example, can such be particulates A is to be deposited on the conveyor 8 to be conveyed. Other supplies temporarily the reservoir provided for storing, the first fine particles D ₁ to the storage tank of the granules A between the first indirect heating type dryer 2 and the second indirect heat type dryer 3 You may do it. The first fine particles D ₁ mixed with the other granular materials A are supplied to the second indirectly heated dryer 3 together with the other granular materials A.

(D) Process The carrier gas G discharged from the second indirectly heated dryer 3 is sent to the second bag filter 5. In the second bag filter 5, the second fine particles D ₂ contained in the carrier gas G is collected.

The indirect heating type drying apparatus 1 is also provided with an N ₂ blaster 11 near the entrance of the second bag filter 5. The N ₂ blaster 11 removes dust (second fine particles D ₂ ) adhering or accumulating on the inlet of the second bag filter 5 and the pipe connecting the second indirectly heated dryer 3 and the second bag filter 5. Can do.

Second fine particles D ₂ that is the recovered, the second mixing means (not shown), is mixed with the dry granulate B obtained in the above step (B). At this time, for example, a storage tank for temporarily storing the dried granular material B can be provided under the discharge casing 9, and the second fine particles can be supplied to the storage tank. Mixed with the second particle D ₂ and dry granules B is subjected to a subsequent step if desired.

(Other processes)
The carrier gas G from which dust (first or second fine particles D ₁ and D ₂ ) has been separated by the bag filters 4 and 5 is sent to the cooling tower 12 and cooled. Aggregated liquid C generated by cooling is discharged out of the system via pump 13. On the other hand, the cooled carrier gas G is blown by the blower 14 and supplied again to the first and second indirectly heated dryers 2 and 3. A heater (not shown) is provided between the blower 14 and each of the indirectly heated dryers 2 and 3 so that the carrier gas G can be heated to a predetermined temperature.

(effect)
In the method of indirectly heating and drying the granular material, in the step (D), the second fine particles D ₂ contained in the carrier gas G discharged from the second indirect heating type dryer 3 are obtained by the step (B). Mix with granulate B. In this way, the second can reduce the amount of particulate D ₂ contained in the carrier gas G discharged from the second indirect heating type dryer 3, first used in the recovery of the second fine particles D ₂ it is possible to reduce the storage amount of the second particles D ₂ to the secondary bag filter 5. Therefore, according to the indirect heat drying method, the stability of the pressure balance of the carrier gas G in the system can be enhanced. Further, the second fine particles D ₂ is the particle size among the dried the granules A is small, because the drying is one that has progressed sufficiently, the indirect heat-drying method, compared to the conventional drying method It does not substantially reduce the drying efficiency.

Furthermore, according to the indirect heat drying method, only the second fine particles D ₂ separated once are processed, and the second fine particles D ₂ after the treatment are mixed with the dried granular material B obtained in the step (B). be able to. Such treatment, include spraying the liquid (water) with respect to the second fine particles D ₂ is, by doing so, suppressing the generation of dust dried granules, of liquid to be used in this The amount can be reduced.

Further, the second fine particles D ₂ separated and mixed with an adhesive or the like, the mixture can be mixed with dry granules B. By doing in this way, the moldability at the time of shape | molding the obtained dried material (mixture of a dry granular material and 2nd microparticles | fine-particles) to a predetermined size can be improved. Moreover, the usage-amount of the adhesive agent etc. which are used in order to improve a moldability can be reduced by doing in this way.

Examples of the second average particle size of the bag filter 5 the second fine particles recovered in ((D) Step) D _2, is preferably 10μm or less. Since the fine particles having such a particle diameter are relatively sufficiently dried in the step (A), a decrease in drying efficiency can be suppressed in the indirect heat drying method. The average particle diameter of the second fine particles D ₂ can be adjusted, such as by changing the mesh size of the second bag filter 5. As said average particle diameter, 1 micrometer or more and 5 micrometers or less are more preferable. The average particle diameter of the second fine particles D ₂ is the case of less than the above lower limit, it is necessary to finely eye second bag filter 5, the stability of the pressure balance of the carrier gas G may be decreased.

The second fine particles D ₂ collected in the second bag filter 5 (step (D)) and the dried particulate matter B discharged from the second indirectly heated dryer 3 (the drying obtained in the step (B)) The mass ratio to the granular material is preferably from 1:99 to 1: 3, and more preferably from 1:19 to 1: 6. Such a second particulate D ₂ amounts to separate, it is possible to achieve the improvement of the stability of the pressure balance of the carrier gas G, and suppression of decrease in the drying efficiency together. When the amount of the second fine particles is less than the above ratio, the carrier gas pressure balance may become unstable due to the large amount of fine particles remaining in the system. On the contrary, when the amount of the second fine particles exceeds the above ratio, a relatively large amount of fine particles do not pass through the second indirect heating dryer 3, and thus the drying efficiency may be reduced. The ratio between the second fine particles D ₂ and dry granules B can be carried out such as by adjusting the eye size and the second bag filter 5, a carrier gas supply amount in the second indirect heat type dryer 3 .

The flow rate of the carrier gas G in the second indirectly heated dryer 3 is not particularly limited, but is about 0.1 to 10 times (molar ratio) of the solvent evaporation amount in the second indirectly heated dryer 3. Is preferred. With the flow rate of this range, while dried sufficiently granules, can be separated second particles D ₂ of the desired amount. Further, the flow rate per filter area of the carrier gas G passing through the bag filters (the first bag filter 4 and the second bag filter 5) is set to 0.1 m ³ / s · m ² or more and 10 m ³ / s · m ² or less. It is also preferable. By doing in this way, dust can be effectively collected in the bag filter.

Further, in the said indirect heat drying method, the recovery of the first particle D ₁ and the second fine particles D _2, respectively are performed using a bag filter. By using the bag filter as described above, dust (first or second fine particles) having a desired particle diameter can be efficiently recovered. Moreover, the waste water treatment required in a wet scrubber or the like is also unnecessary.

  Furthermore, in the indirect heating type drying method, each bag filter or the like can be obtained by supplying the carrier gas G to the flow of the particulate matter A in a parallel flow in the step (A) and in a counter flow in the step (B). Generation of condensation of the carrier gas G in the system is suppressed. The reason for this will be described below. In the first indirect heating type dryer 2, on the carrier gas outlet side of the dryer 2, that is, on the dried product outlet side, the carrier gas G contains an evaporated liquid component, and its dew point is high. However, the drying of the dried product (granular material A) is progressing, and the temperature of the dried product (granular material A) and the carrier gas G is high. Therefore, the temperature difference between the gas temperature and the dew point can be increased, and dew condensation is unlikely to occur in the first bag filter 4. On the other hand, in the second indirect heating type dryer 3, the object to be dried (granular material A) has been dried to the limit liquid content by the first indirect heating type dryer 2, and the temperature has risen. The temperature difference between temperature and dew point can be increased. Therefore, condensation is less likely to occur even in the second bag filter 5 provided for the second indirect heating dryer 3.

  Further, in the indirect heating drying method and the drying apparatus 1, the carrier gas G cooling means (cooling tower 12) and the carrier gas G heating means are provided in this order with respect to the carrier gas flow. By doing in this way, the dew point of the carrier gas supplied to each indirect heating type dryer 2 and 3 can be reduced.

  According to the indirect heating and drying method, since condensation is reduced by the carrier gas G circulating in this way, dust (fine particles) can be easily collected by the bag filters 4 and 5, Instability of pressure balance due to filter clogging caused by condensation is further reduced.

<Modified coal production equipment>
The modified coal production apparatus of the present invention mainly includes a mixing means, a heating means, a solid-liquid separation means, and a drying means.

  The mixing means mixes granular porous charcoal and oil to obtain a raw material slurry. The mixing means is not particularly limited, and a known mixing tank equipped with a stirring blade or the like can be used.

  The heating means heats the raw material slurry to obtain a dehydrated slurry. The heating means is not particularly limited, and a known heat exchanger, evaporator or the like can be used.

  The solid-liquid separation means separates the dehydrated slurry into modified porous charcoal and oil. The solid-liquid separation means is not particularly limited, and a known solid-liquid separator such as a centrifugal separator or a filter can be used.

  The drying means dries the separated modified porous charcoal. The indirect heating type drying apparatus is used as this drying means.

  Below, the usage method of the said modified coal manufacturing apparatus is demonstrated as a manufacturing method of modified coal.

<Method for producing reformed coal>
The method for producing the modified coal of the present invention comprises:
(Α) A step of mixing raw material slurry by mixing granular porous charcoal and oil (mixing step),
(Β) heating the raw material slurry to obtain a dehydrated slurry (heating step),
(Γ) a step of separating the dehydrated slurry into modified porous coal and oil (solid-liquid separation step); and (δ) a step of drying the separated modified porous coal (drying step).
Have

  In addition, you may have further a preheating process between ((alpha)) mixing process and ((beta)) heating process prior to ((alpha)) mixing process. Hereinafter, each step will be described in detail.

(Crushing process)
In the pulverization step, the porous coal X is pulverized into a granular material having a preferable particle size prior to the mixing step. This pulverization can be performed by using a known pulverizer or the like. The particle diameter of the granular porous charcoal thus pulverized and used for the mixing step is not particularly limited, and is, for example, 0.05 mm to 2.0 mm, preferably 0.1 mm to 0.5 mm. can do.

(Α) Mixing Step In the mixing step, the above-mentioned mixing means is used to mix granular porous charcoal X and oil to obtain a raw material slurry. This oil is preferably a mixed oil containing a heavy oil and a solvent oil. Hereinafter, it demonstrates as an example using this mixed oil.

  Porous coal is a so-called low-grade coal that contains a large amount of moisture and is desired to be dehydrated. The water content of the porous coal is, for example, 20 to 70% by mass. Examples of such porous coal include lignite, lignite, and sub-bituminous coal (eg, Samarangau coal).

  The heavy oil component is an oil composed of or containing a heavy component that does not substantially exhibit a vapor pressure even at 400 ° C., and asphalt or the like can be used.

  The solvent oil component is an oil that disperses the heavy oil component. As this solvent oil component, a light boiling oil component is preferred from the viewpoints of affinity with a heavy oil component, handleability as a slurry, ease of penetration into pores, and the like. Specifically, petroleum-based oils (light oil, kerosene, heavy oil, etc.) having a boiling point of 100 ° C. or higher, preferably 300 ° C. or lower are preferable.

  When such a mixed oil of heavy oil and solvent oil is used, the mixed oil exhibits appropriate fluidity. Therefore, in the said manufacturing method, the penetration | invasion into the pore of the porous coal of the heavy oil component which cannot be fulfilled with only a heavy oil component is accelerated | stimulated. As content of the heavy oil content in the said mixed oil, it can be set as 0.25 mass% or more and 15 mass% or less, for example.

  The mixing ratio of the mixed oil with respect to the porous coal is not particularly limited. For example, the mass ratio of the heavy oil to the porous charcoal is 0.5% by mass or more and 30% by mass or less, preferably 0.5% by mass or more and 5% by mass or less.

  The conditions for the mixing are not particularly limited, and may be usually performed at a temperature of 40 ° C. to 100 ° C. under atmospheric pressure.

(Preheating process)
The raw material slurry obtained in the mixing step is usually preheated prior to the heating step. There are no particular restrictions on the preheating conditions, and heating is usually performed to near the boiling point of water at the operating pressure.

(Β) Heating step In the heating step, the raw material slurry is heated using the heating means to obtain a dehydrated slurry. At this time, the dehydration of the porous coal proceeds and the mixed oil is impregnated into the pores of the porous coal. Specifically, the inner surface of the pores of the porous coal is successively covered with the mixed oil containing the heavy oil, and almost the entire area of the pore opening is filled with the mixed oil containing the heavy oil. The heavy oil in the mixed oil is easily selectively adsorbed to the active sites, and when attached, it is difficult to separate, so that the heavy oil is preferentially attached over the solvent oil. Thus, it becomes possible to lose the spontaneous ignition by blocking the inner surface of the pores from the outside air. Moreover, since a large amount of water is dehydrated and removed, and the heavy oil-containing mixed oil, particularly heavy oil, preferentially fills the pores, an increase in calories as a whole of the porous coal is achieved.

  It is preferable to perform the said heating under pressure, for example, 200-1500 kPa is suitable. In addition, the heating time is not generally defined because a series of steps are usually carried out by continuous operation, and it is sufficient that the dehydration of the porous coal and the impregnation of the mixed oil into the pores can be achieved.

  In this heating step, water vapor generated by heating is removed. Water vapor generated and removed in this step can be recovered and increased in pressure, and used as a heating source in a preheating step or a heating step.

(Γ) Solid-liquid separation step In the solid-liquid separation step, the dehydrated slurry is separated into modified porous coal and mixed oil using the solid-liquid separation means. The mixed oil (oil Z) separated in this step can be reused in the above (α) mixing step.

(Δ) Drying step In the drying step, the above-described modified porous coal is dried using the indirect heating type drying apparatus 1. The specific drying method is as described above as the method for indirectly heating and drying the granular material, and the granular material as the material to be dried is the separated granular modified porous charcoal.

  Specifically, for example, in the first indirect heating dryer, the oil (particularly solvent oil) is evaporated at a residence time of about 30 to 120 minutes and a heating temperature of about 150 to 250 ° C. Subsequently, also in the second indirect heating type dryer, the oil component Z (particularly, the solvent oil component) is evaporated at a residence time of about 30 to 120 minutes and a heating temperature of about 150 to 250 ° C. The evaporated oil component Z is recovered and can be reused in the (α) mixing step.

  By this drying step, the liquid content of the modified porous charcoal can be, for example, 10 to 50% by mass to less than 10%, preferably about 0.1% to 3%. Moreover, the dried modified porous coal Y can be cooled and molded as desired to obtain modified coal.

In the (δ) drying step, as the step (D), the second fine particles D ₂ contained in the carrier gas G discharged from the second indirectly heated dryer 3 as described above are collected, and the step (B) is performed. Is mixed with the dried granular material (modified porous charcoal) obtained in In this way, you can reduce the amount of second particulate D ₂ contained in the carrier gas G discharged from the second indirect heating type dryer 3, used for the recovery of the second fine particles D ₂ bug it is possible to reduce the storage amount of the second particles D ₂ to the filter 5 and the like. Therefore, according to the said manufacturing method, stability of the pressure balance of the carrier gas used at a drying process can be improved.

Further, in this drying step for the second particles D ₂ which once separated, sprayed or water, may be subjected to additional processing such as mixing with the adhesive. By mixing the second fine particles D ₂ subjected to such treatment with other modified porous coal (dried granular material B), it is possible to effectively suppress dust generation of the obtained modified coal and to form a briquette. The moldability at the time of molding into can be improved.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

[Example 1]
The modified coal was manufactured along the flow chart of FIG. 3 and continuously using the indirect heating type drying apparatus of FIG. 1 under the following conditions.
・ Crushing process Raw material: Samarangau charcoal Crushing condition: Maximum particle size 3000 μm, average particle size about 150 μm
-Mixing process The newly prepared mixed oil [kerosene 1kg / h, asphalt 1kg / h] was supplied to Samarangau charcoal 180kg / h and circulating oil 248kg / h, and the raw material slurry was adjusted (70 degreeC, 100kPa).
Heating process Feed rate of raw material slurry to heat exchanger (evaporator): 430 kg / h
Heating conditions: 137 ° C, 400 kPa
・ Solid-liquid separation process 130 ℃, 100kPa
-Drying process 1st dryer; Steam tube type dryer (Number of tubes: 12 pieces, Axial length: 5000 mm, heating temperature (carrier gas (CG ₁ ) temperature)): about 210 ° C, modified porous charcoal residence time 60 Minute 2nd dryer; steam tube type dryer (number of tubes: 6 (+6 does not supply steam), axial length: 5000 mm, heating temperature (carrier gas (CG ₂ ) temperature); Modified porous charcoal residence time 60 minutes Manufactured under the above conditions, immediately after the drying step, modified porous charcoal was obtained at 100 kg / h.

  The liquid content of the obtained modified porous charcoal was about 1% by mass.

  The average particle diameter (cumulative 50% average diameter) of the second fine particles collected by the second bag filter was about 3 μm. The mass ratio of the recovered second fine particles to the dried granular material (modified coal) directly discharged from the second indirectly heated dryer 3 was about 1: 9.

  Moreover, the pressure gauge in the system provided in the second bag filter was stable in the range of 0.6 to 1.0 kPa during operation for 100 hours.

[Comparative Example 1]
1 except that the dust (second fine particles) collected by the second bag filter 5 is mixed with the particulate matter provided to the second indirectly heated dryer 3 in the indirect heating dryer of FIG. In the same manner as in Example 1, modified coal was produced.

  The liquid content of the obtained modified porous charcoal was about 1% by mass.

In addition, while operating for 100 hours, the pressure gauge in the system provided in the second bag filter rose to 1.6 kPa. Therefore, the amount of circulating gas in the second indirectly heated dryer 3 was reduced. Or, since the cleaning pulse setting of the bag filter was changed, the amount of N ₂ used increased.

  As described above, the indirect heating drying method of the granular material of the present invention is effective for drying various granular materials such as porous charcoal, sludge, food residue, chemicals, etc., particularly modified porous charcoal. Can be used.

1 indirect heating type drying device 2 first indirect heating type dryer 3 second indirect heat type dryer 4 first bag filter 5 second bag filter 6 screw conveyor 7 discharge casing 8 conveyer 9 discharge casing 10, 11 N ₂ Blaster 12 Cooling tower 13 Pump 14 Blower 100 Steam tube dryer 101 Rotating cylinder 102 Heating tube 103 Supply port 104 Discharge port 105 Carrier gas supply port 106 Carrier gas discharge port 107a, 107b Base 108a, 108b Bearing roller 109a, 109b Ring 110 Driven gear 111 Drive gear 112 Motor 113 Reduction gear 114 Rotary joint 115 Heat medium inlet pipe 116 Heat medium outlet pipe A Granule B Dry granule C Aggregate D ₁ First fine particle D ₂ Second fine particle G Carrier gas X Porous coal Y Modification Porous coal Z Minute

Claims (6)

A rotating cylinder provided rotatably around an axis, a plurality of heating pipes arranged in parallel to the axis in the rotating cylinder, and a carrier gas supplied from one side of the rotating cylinder and discharged to the other side Two indirect heating dryers each having a carrier gas distribution means
(A) In the first indirect heating type dryer, a carrier gas is supplied so as to be parallel to the flow of the granular material, and the granular material is dried, and (B) a second indirect heating type dryer. In the method for indirectly heating and drying a granular material, the method includes a step of supplying a carrier gas so as to be countercurrent to the flow of the granular material, and further drying the granular material to obtain a dried granular material,
(C) collecting the first fine particles contained in the carrier gas discharged from the first indirect heating type dryer and mixing with the particulate matter provided to the step (B), and (D) the second Indirect heating drying of the granular material, further comprising a step of collecting the second fine particles contained in the carrier gas discharged from the indirect heating type dryer and mixing with the dried granular material obtained in the step (B). Method.   The method for indirectly heating and drying a granular material according to claim 1, wherein the second fine particles recovered in the step (D) have an average particle size of 10 µm or less.   The mass ratio of the second fine particles recovered in the step (D) and the dried granular material obtained in the step (B) is 1:99 or more and 1: 3 or less. Indirect heating drying method for granular materials. (Α) a step of mixing raw material porous carbon and oil to obtain a raw slurry;
(Β) heating the raw material slurry to obtain a dehydrated slurry;
(Γ) a process for separating the dehydrated slurry into modified porous coal and oil, and (δ) a step of drying the separated modified porous coal,
In the said ((delta)) process, the manufacturing method of the modified coal characterized by using the indirect heating drying method of the granular material of Claim 1, Claim 2, or Claim 3. Equipped with a first indirect heating dryer and a second indirect heating dryer,
Each of the indirect heating dryers includes a rotating cylinder that is rotatably provided around an axis, a plurality of heating tubes that are disposed in the rotating cylinder in parallel with the axis, and a carrier gas that is supplied to the rotating cylinder. Carrier gas distribution means for supplying from one side and discharging to the other side,
Arranged to receive the dried product obtained from the first indirectly heated dryer as the material to be dried of the second indirectly heated dryer,
The carrier gas distribution means is configured so that the flow of the material to be dried in each indirect heating dryer is a parallel flow in the first indirect heating dryer and a countercurrent in the second indirect heating dryer. An indirect heating type drying apparatus for supplying gas,
A first recovery means for recovering the first fine particles contained in the carrier gas discharged from the first indirectly heated dryer;
A first mixing means for mixing the first fine particles with the granular material provided to the second indirect heating type dryer;
Recovery means for recovering the second fine particles contained in the carrier gas discharged from the second indirectly heated dryer, and second mixing means for mixing the second fine particles with the dried product obtained from the second indirectly heated dryer An indirect heating type drying apparatus, further comprising: Mixing means for mixing granular porous charcoal and oil to obtain a raw material slurry,
Heating means for heating the raw material slurry to obtain a dehydrated slurry;
A reformed coal production apparatus comprising solid-liquid separation means for separating the dewatered slurry into modified porous coal and oil, and drying means for drying the separated modified porous coal,
A modified coal production apparatus, wherein the drying means is the indirect heating type drying apparatus according to claim 5.

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